|
|
| (17 intermediate revisions by 2 users not shown) |
| Line 1: |
Line 1: |
| | <StructureSection load='1ee5' size='340' side='right' caption='Structure of yeast importin α NLS-binding domain (grey) complex with nucleoplasmin peptide (green) (PDB code [[1ee5]]).' scene=''> |
|
| |
|
| <StructureSection load='1ee5' size='340' side='right' caption='Structure of yeast importin α NLS-binding domain complex with nucleoplasmin peptide (PDB code [[1ee5]]).' scene=''>
| | == Function == |
|
| |
|
| == Function ==
| | '''Importins''' (IPO) mediate the import of cellular proteins into the nucleus by binding to the '''N'''uclear '''L'''ocalization '''S'''ignal (NLS). IPO has 2 subunits: α and β. '''IPO-α''' is an adaptor protein which binds the NLS<ref>PMID:9759490</ref>. IPOs can contain one or two NLS motifs. |
| | *'''IPO-α''' contains several armadillo repeats with two NLS-binding sites and an IPO-β binding (IBB) site. |
| | *'''IPO-β''' contains 19 HEAT (solenoid domain) repeats. Many nuclear proteins contain Phe-Gly sequences which can bind to HEAT repeats and thus be transported. |
| | *'''IPO-4''' binds histones H3 and H4 and histone chaperone ASF1 for nuclear import<ref>PMID:36103578</ref>. |
| | *'''IPO-7''' drives the nuclear import of the regulator of mechanotransduction pathway YAP<ref>PMID:35246520</ref>. |
| | *'''IPO-9''' binds histones H2A and H2B for nuclear import<ref>PMID:30855230</ref>. |
| | *'''IPO-13''' has a role in oxidative stress-dependent nuclear export<ref>PMID:34625540</ref>. |
|
| |
|
| '''Importins''' (IPO) mediate the import of cellular proteins into the nucleus by binding to the nuclear localization signal (NLS). IMP has 2 subunits: α and β. IPO-α is an adaptor protein which binds the NLS. Proteins can contain one or two NLS motifs. IPO-α contains several armadillo repeats with two NLS-binding sites and an IPO-β binding site (IBB). IPO-β contains 19 HEAT repeats. Many nuclear proteins contain Phe-Gly sequences which can bind to HEAT repeats and thus be transported.
| | See also [[Protein Transport Membrane Protein]]. |
|
| |
|
| == Disease == | | == Disease == |
| | IPO-α isoform expression is altered in many kinds of cancer. |
|
| |
|
| == Relevance == | | == Relevance == |
| | Specific IPO-α isoforms are critical in nerve regenerative response after injury. Loss of IPO-α expression in aging myocardial cells could make recovery after heart disease in elderly patients more difficult<ref>PMID:25656054</ref>. |
|
| |
|
| == Structural highlights == | | == Structural highlights == |
|
| |
|
| ==3D structures of importin== | | ==3D structures of importin== |
| | [[Importin 3D structures]] |
|
| |
|
| Updated on {{REVISIONDAY2}}-{{MONTHNAME|{{REVISIONMONTH}}}}-{{REVISIONYEAR}}
| | </StructureSection> |
| | |
| '''IPO-α'''
| |
| | |
| [[1ial]] – mIPO residues 44-496 – mouse<br />
| |
| [[1bk5]] – yIPO NLS-binding domain - yeast<br />
| |
| | |
| ''IPO-α complex with NLS peptide''
| |
| | |
| [[1ejl]] – mIPO NLS-binding domain + SV40 large T antigen<br />
| |
| [[1ejy]] – mIPO NLS-binding domain + nucleoplasmin <br />
| |
| [[2ynr]] – mIPO NLS-binding domain + B54NLS <br />
| |
| [[1bk6]] – yIPO NLS-binding domain + SV40 large T antigen<br />
| |
| [[1ee4]] – yIPO NLS-binding domain (mutant) + c-Myc<br />
| |
| [[1ee5]] – yIPO NLS-binding domain (mutant) + nucleoplasmin<br />
| |
| [[1un0]], [[2c1t]] – yIPO NLS-binding domain (mutant) + Nup2<br />
| |
| | |
| ''IPO-α complex with protein''
| |
| | |
| [[1wa5]] – yIPO NLS-binding domain + GTPase Ran + IPO-α re-exporter<br />
| |
| | |
| '''IPO-α 1'''
| |
| | |
| ''IPO-α 1 complex with NLS peptide''
| |
| | |
| [[4mz5]], [[4mz6]] – mIPO NLS-binding domain + dUTPase<br />
| |
| [[4oih]] – mIPO NLS-binding domain + guanine nucleotide exchange factor SRM1<br />
| |
| | |
| ''IPO-α 1 complex with protein''
| |
| | |
| [[2jdq]] – hIPO NLS-binding domain + polymerase basic protein 2 C terminal<br />
| |
| [[3tj3]] – hIPO NLS-binding domain + Nup50 N terminal<br />
| |
| [[2jdq]] – hIPO NLS-binding domain + telomerase reverse transcriptase peptide<br />
| |
| | |
| '''IPO-α 2'''
| |
| | |
| [[3tpo]] – mIPO<br />
| |
| [[1iq1]] – mIPO NLS-binding + autoinhibitory peptide domains<br />
| |
| [[4e4v]] – hIPO NLS-binding domain (mutant) - human <br />
| |
| | |
| ''IPO-α 2 complex with NLS peptide''
| |
| | |
| [[1pjm]] – mIPO NLS-binding domain + retinoblastoma-associated protein<br />
| |
| [[1pjn]] – mIPO NLS-binding domain + histone-binding protein N1/N2<br />
| |
| [[1q1s]], [[1q1t]] – mIPO NLS-binding domain + SV40 large T antigen<br />
| |
| [[1y2a]], [[3q5u]] – mIPO NLS-binding domain + phospholipid scramblase <br />
| |
| [[2c1m]] – mIPO NLS-binding domain + Nup50<br />
| |
| [[3btr]] – mIPO NLS-binding domain + androgen receptor<br />
| |
| [[3knd]] – mIPO NLS-binding domain + targeting protein for KXLP2<br />
| |
| [[3l3q]] – mIPO NLS-binding domain + library peptide<br />
| |
| [[3oqs]] – mIPO NLS-binding domain + CLIC4<br />
| |
| [[3rz9]] – mIPO NLS-binding domain + KU80<br />
| |
| [[3rzx]] – mIPO NLS-binding domain + KU70<br />
| |
| [[3tpm]] – mIPO NLS-binding domain + MAL<br />
| |
| [[3ve6]] – mIPO NLS-binding domain + Venezuelan equine encephalitis virus<br />
| |
| [[3uvu]] – mIPO NLS-binding domain + flap endonuclease<br />
| |
| [[3ukw]], [[3ukx]] – mIPO NLS-binding domain + BIMAX<br />
| |
| [[3uky]], [[3ukz]], [[3ul0]] – mIPO NLS-binding domain + nuclear CAP-binding protein<br />
| |
| [[3ul1]] – mIPO NLS-binding domain + nucleoplasmin <br />
| |
| [[4htv]] – mIPO NLS-binding domain + capsid protein <br />
| |
| [[4ba3]] – mIPO NLS-binding domain + A89NLS <br />
| |
| [[3zio]], [[3zip]], [[3ziq]], [[3zir]] – mIPO NLS-binding domain + minor site-specific NLS <br />
| |
| [[3zin]] – mIPO NLS-binding domain + nucleolar RNA helicase<br />
| |
| | |
| ''IPO-α 2 complex with protein''
| |
| | |
| [[3fex]], [[3fey]] – mIPO NLS-binding domain + nuclear CAP-binding protein<br />
| |
| | |
| '''IPO-β 1'''
| |
| | |
| [[3nd2]] – yIPO <br />
| |
| [[1gcj]] – mIPO N terminal<br />
| |
| | |
| ''IPO-β 1 complex with protein''
| |
| | |
| [[1qgx]], [[1qgr]] – hIPO + IPO-α 2 IBB domain<br />
| |
| [[1ibr]] – hIPO + GTPase Ran<br />
| |
| [[2bku]], [[3ea5]] – yIPO + GTPase Ran<br />
| |
| [[1f59]], [[1o6p]], [[1o6o]] – hIPO + FXFG nucleoporin repeats<br />
| |
| [[1m5n]] – hIPO HEAT repeats 1-11 + parathyroid hormone-related protein NLS peptide<br />
| |
| [[2p8q]], [[2q5d]], [[2qna]], [[3lww]] – hIPO + RNA U transporter N terminal<br />
| |
| [[1qgr]], [[3w5k]] – hIPO + zinc finger protein SNAI1<br />
| |
| [[2bpt]] – yIPO + Nup1<br />
| |
| [[1ukl]] – mIPO + SREBP-2<br />
| |
| | |
| '''IPO-β 2 (Transportin 1)'''
| |
| | |
| [[2z5j]], [[2qmr]] – hIPO <br />
| |
| | |
| ''IPO-β 2 complex with protein''
| |
| | |
| [[2h4m]], [[2ot8]], [[2z5n]] – hIPO + hnRNP peptide<br />
| |
| [[2z5k]], [[2z5m]] – hIPO + nuclear RNA export factor peptide<br />
| |
| [[2z5o]] – hIPO + JKTBP peptide<br />
| |
| [[4fdd]], [[4jlq]], [[4oo6]] – hIPO + RNA binding protein peptide<br />
| |
| [[4fq3]] – hIPO + FUS peptide<br />
| |
| | |
| '''IPO-13'''
| |
| | |
| [[2x19]] – hIPO + GTPase Ran<br />
| |
| [[2xwu]] – hIPO + UBC9<br />
| |
| [[3zjy]] – hIPO + GTPase Ran + EIF-1A<br />
| |
| | |
|
| |
|
| == References == | | == References == |
